[Bug lto/102426] New: [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[Bug lto/102426] New: [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

            Bug ID: 102426
           Summary: [12 regression] Fix for PR 49664 breaks Solaris
                    bootstrap with gld
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: marxin at gcc dot gnu.org, pinskia at gcc dot gnu.org
  Target Milestone: ---
              Host: *-*-solaris2.11

By rev 48b3caffcacc99adf72ba1be189a7d9ebc4190be, master bootstrap is broken on 
Solaris when configured to use GNU ld:

The failure occurs trying to link lto-plugin.so:

libtool: link:
           /var/gcc/regression/master/11.4-gcc-gas-gld/build/./prev-gcc/xgcc
-B/var/gcc/regression/master/11.4-gcc-gas-gld/build/./prev-gcc/
-B/vol/gcc/i386-pc-solaris2.11/bin/ -B/vol/gcc/i386-pc-solaris2.11/bin/
-B/vol/gcc/i386-pc-solaris2.11/lib/ -isystem
/vol/gcc/i386-pc-solaris2.11/include -isystem
/vol/gcc/i386-pc-solaris2.11/sys-include   -fno-checking -shared -Wl,-z
-Wl,text -Wl,-M -Wl,.libs/liblto_plugin.so.exp -Wl,-h -Wl,liblto_plugin.so -o
.libs/liblto_plugin.so  .libs/lto-plugin.o    -static-libgcc -static-libstdc++
-static-libgcc ../libiberty/pic/libiberty.a
/vol/gcc/bin/gld-2.37:.libs/liblto_plugin.so.exp: file format not recognized;
treating as linker script
/vol/gcc/bin/gld-2.37:.libs/liblto_plugin.so.exp:1: syntax error
collect2: error: ld returned 1 exit status
make[4]: *** [Makefile:466: liblto_plugin.la] Error 1

liblto_plugin.so.exp contains

{ global:
onload;
local: *; };

AFAICT, the issue is caused by libtool assuming that gcc on Solaris always
uses the native linker, which is wrong: I regularly test both ld and gld
configurations and this is also documented in install.texi.

The invocation above stems from libtool.m4 after l.5035:

    solaris*)
      _LT_TAGVAR(no_undefined_flag, $1)=' -z defs'
      if test "$GCC" = yes; then
        wlarc='${wl}'
        _LT_TAGVAR(archive_cmds, $1)='$CC -shared ${wl}-z ${wl}text ${wl}-h
${wl}$soname -o $lib $libobjs $deplibs $compiler_flags'
        _LT_TAGVAR(archive_expsym_cmds, $1)='echo "{ global:" > $lib.exp~cat
$export_symbols | $SED -e "s/\(.*\)/\1;/" >> $lib.exp~echo "local: *; };" >>
$lib.exp~
          $CC -shared ${wl}-z ${wl}text ${wl}-M ${wl}$lib.exp ${wl}-h
${wl}$soname -o $lib $libobjs $deplibs $compiler_flags~$RM $lib.exp'

The question is how to deal with this: libtool is unmaintained for 2 1/2 years
now.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Rainer Orth <ro at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So libtool has been broken for over 15 years for this option and we are only
noticing now. Grrrr.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-09-21
           Keywords|                            |build
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It seems like only this feature which libtool gets wrong.

There are other places where lt_cv_prog_gnu_ld/with_gnu_ld is checked.
So it should not be hard to add this check there.

I might come up with a patch which adds the check but it might not for a week.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #3 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> It seems like only this feature which libtool gets wrong.
>
> There are other places where lt_cv_prog_gnu_ld/with_gnu_ld is checked.
> So it should not be hard to add this check there.
>
> I might come up with a patch which adds the check but it might not for a week.

No need to hurry: I only bootstrap with gld once a week anyway and can
easily backout the patch locally until you've got something ready.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Mine.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org

--- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
note that same error happens on older x86_64-linux debian boxes.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jan Hubicka from comment #5)
> note that same error happens on older x86_64-linux debian boxes.

That has to be a totally different issue from here. This is specificially about
solaris specific code in libtool.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, shouldn't we instead of the -export-symbols-regex use a version script?
We have it in multiple lib* directories, so presumably it should work reliably.
Say the version script in libssp/ is quite simple, small configure.ac hunk,
small Makefile.am hunk, small version script.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #8 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> So, shouldn't we instead of the -export-symbols-regex use a version script?

We certainly could, but IIUC this would lose the functionality on
non-ELF targets that do support -export-symbols-regex in a different
way.  No idea if this is deemed acceptable...

> We have it in multiple lib* directories, so presumably it should work reliably.
> Say the version script in libssp/ is quite simple, small configure.ac hunk,
> small Makefile.am hunk, small version script.

We could even simplify the libssp example: given that we only want to
export one single symbol, we don't need the make_sunver.pl magic, only
the difference between -Wl,--version-script and -Wl,-M.

Just in case you wonder, we still need that script for libssp on
Solaris: mempcpy and thus __mempcpy_chk don't exist on Solaris, thus
that symbol needs to be filtered from ssp.map.

I long meant to unify all those instances of version script handling,
but that turned out to be a terrible can of worms and is certainly not
GCC 12 material.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to ro@CeBiTec.Uni-Bielefeld.DE from comment #8)
> > --- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> > So, shouldn't we instead of the -export-symbols-regex use a version script?
> 
> We certainly could, but IIUC this would lose the functionality on
> non-ELF targets that do support -export-symbols-regex in a different
> way.  No idea if this is deemed acceptable...

The world doesn't end if other symbols are exported, it worked that way for
years.
Perhaps we could test in configure whether -export-symbols-regex works and only
use a fallback if it doesn't?  Or decide it based on target triplet,
do those GNU and SUN version script checks and if neither of them works, fall
back to -export-symbols-regex ?
gld supports version scripts like:
{ global: onload; local: *; };
which makes onload a non-versioned GLOBAL symbol while everything else LOCAL,
does Sun ld support that too or similar?

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #10 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> (In reply to ro@CeBiTec.Uni-Bielefeld.DE from comment #8)
>> > --- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
>> > So, shouldn't we instead of the -export-symbols-regex use a version script?
>> 
>> We certainly could, but IIUC this would lose the functionality on
>> non-ELF targets that do support -export-symbols-regex in a different
>> way.  No idea if this is deemed acceptable...
>
> The world doesn't end if other symbols are exported, it worked that way for
> years.

True ;-)

> Perhaps we could test in configure whether -export-symbols-regex works and only
> use a fallback if it doesn't?  Or decide it based on target triplet,
> do those GNU and SUN version script checks and if neither of them works, fall
> back to -export-symbols-regex ?

I wouldn't check triplets, but instead do the symbol versioning check
and, if that fails, use -export-symbols-regex.

> gld supports version scripts like:
> { global: onload; local: *; };
> which makes onload a non-versioned GLOBAL symbol while everything else LOCAL,
> does Sun ld support that too or similar?

That's exactly the Sun ld syntax.  After all, they came up with that
before gld adopted it...

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 52656
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52656&action=edit
gcc12-pr102426.patch

So like this then?

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #12 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> Created attachment 52656
>   --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52656&action=edit
> gcc12-pr102426.patch
>
> So like this then?

I included the patch in last night's bootstraps (sparc-sun-solaris2.11,
as/ld, gas/ld, and i386-pc-solaris2.11, as/ld, gas/ld, gas/gld).  Worked
fine: in all cases, the only exported global symbol is onload, as
expected.

Thanks.

In the end, there isn't much point in building the lto-plugin when
Solaris ld (or any linker not supporting the gld/gold plugin interface)
is in use.  I think I checked at one point if this could be fitted in
with the linker's support and/or auditing interfaces

https://docs.oracle.com/cd/E37838_01/html/E36783/chapter6-1238.html#scrolltoc

but cannot find my notes anymore and, I believe, concluded that they
don't match.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:6ee5892638526366fc3d8a1f4426f3cc278ea061

commit r12-7752-g6ee5892638526366fc3d8a1f4426f3cc278ea061
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Mar 22 11:02:31 2022 +0100

    lto-plugin: Use GNU ld or Solaris ld version script in preference to
-export-symbols-regex [PR102426]

    As reported, libtool -export-symbols-regex doesn't work on Solaris
    when using GNU ld instead of Sun ld, libtool just always assumes Sun ld.
    As I'm unsure what is the maintainance status of libtool right now,
    this patch solves it on the lto-plugin side instead, tests at configure
time
    similar way how libssp and other target libraries test for symbol
versioning
    (except omitting the symbol version because we just want one GLOBAL symbol
    and rest of them LOCAL), and will use the current way of
    -export-symbols-regex onload as fallback when this doesn't work.

    2022-03-22  Jakub Jelinek  <jakub@redhat.com>

            PR lto/102426
    lto-plugin/
            * configure.ac (LTO_PLUGIN_USE_SYMVER, LTO_PLUGIN_USE_SYMVER_GNU,
            LTO_PLUGIN_USE_SYMVER_SUN): New test for symbol versioning support.
            * Makefile.am (version_arg, version_dep): Set conditionally based
            on LTO_PLUGIN_USE_SYMVER*.
            (liblto_plugin_la_LDFLAGS): Use $(version_arg) instead of
            -export-symbols-regex onload.
            (liblto_plugin_la_DEPENDENCIES): Depend on $(version_dep).
            * lto-plugin.map: New file.
            * configure: Regenerated.
            * Makefile.in: Regenerated.

[Bug lto/102426] [12 regression] Fix for PR 49664 breaks Solaris bootstrap with gld

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102426

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.